This invention relates generally to improvements in refrigerant float switch assemblies and more particularly, to improvements in the refrigerant float chamber, to the float, and to the electrical proximity switching mechanism used to sense change in the float level and open or close an electrical circuit when a pre-determined float level is obtained.
Heretofore, known electrical switching mechanisms for refrigerant float switches have utilized miniature electrical switches in combination with an externally mounted pivotal arm having a magnet positioned adjacent a distal end thereof. In operation, an elongate stem extending from the top of a float moves in proximity with the magnet, and movement of the magnet toward the rod acts through an external linkage attached to both the arm and switch to actuate the electrical switch. Further, heretofore known electrical switch assemblies have been limited to one such switch per float assembly. Known floats have utilized a solid rod type stem mounted at the top of the float so as to extend into a non-magnetic sealed tube positioned above the float chamber in fluid communication with it. A switch housing having the electrical switch assembly mounted thereon is positioned over and around the sealed tube for actuation by movement of the rod in proximity therewith. The weight of previously used solid stems has slowed reciprocal operative movement of the float.
Additionally, surges of refrigerant into a float chamber may impart an upward velocity of 10 to 20 feet per second to the float which has heretofore been abruptly stopped when the float strikes the top of the float chamber. This results in repetitive shear stress occurring between the float, the stem, and the small stop at the top of the float chamber which shortens the operating life of the float.
A need has developed for improvements in refrigerant float switch assemblies which yield longer operating life, greater reliability, and quicker response, and less wear and tear on parts of the assembly.